public static void SetReference(
this ObjectContext oc,
object target,
string propertyName,
object propertyValue)
{
EntityType entityType = oc.MetadataWorkspace.GetItem <EntityType>(
target.GetType().FullName,
DataSpace.CSpace);
NavigationProperty navProperty = entityType.NavigationProperties[propertyName];
ObjectStateEntry entry = oc.ObjectStateManager.GetObjectStateEntry(target);
EntityReference relatedEnd = (EntityReference)entry.RelationshipManager
.GetRelatedEnd(navProperty.RelationshipType.Name, navProperty.ToEndMember.Name);
if (entry.State != EntityState.Added && !relatedEnd.IsLoaded)
{
relatedEnd.Load();
}
if (propertyValue == null)
{
relatedEnd.EntityKey = null;
}
else
{
EqualityComparer <EntityKey> keycomp = EqualityComparer <EntityKey> .Default;
EntityKey relatedKey = oc.ObjectStateManager.GetObjectStateEntry(target).EntityKey;
if (!keycomp.Equals(relatedEnd.EntityKey, relatedKey))
{
ReflectionHelper.SetProperty(relatedEnd, "Value", propertyValue);
}
}
}
/// <summary>
/// Ensures that entity referenced by <paramref name="entityReference"/> is loaded.
/// </summary>
public static EntityReference <TEntity> GetEnsureLoadedReference <TEntity>(this EntityReference <TEntity> entityReference) where TEntity : EntityObject
{
if (!entityReference.IsLoaded)
{
entityReference.Load();
}
return(entityReference);
}
public static TEntity GetValueAutoLoaded <TEntity>(this EntityReference <TEntity> reference)
where TEntity : class, IEntityWithRelationships
{
if (!reference.IsLoaded)
{
reference.Load();
}
return(reference.Value);
}
public static T LoadAs <R, T>(this EntityReference <R> reference)
where T : class, new()
where R : EntityObject
{
if (reference == null)
{
return(null);
}
reference.Load();
return(reference.Value.CopyProperties <T>());
}
public static T GetKey <T>(this EntityObject entity, string foreignName, string keyName)
{
EntityReference er = entity.GetType().GetProperty(foreignName + "Reference").GetValue(entity, null) as EntityReference;
EntityObject eo = entity.GetType().GetProperty(foreignName).GetValue(entity, null) as EntityObject;
if (er.EntityKey == null)
{
er.Load();
}
else if (!er.IsLoaded)
{
return((T)er.EntityKey.EntityKeyValues[0].Value);
}
return(eo == null ? default(T) : (T)eo.GetType().GetProperty(keyName).GetValue(eo, null));
}
/// <summary>
/// Loads the entity reference or its value if it hasn't already been loaded.
/// </summary>
/// <typeparam name="T">Type of entity reference</typeparam>
/// <param name="entitySource">The source entity which has the entity reference relationship (added, modified or unchanged only)</param>
public void EnsureLoaded <T>(EntityReference <T> entityReference, EntityObject entitySource) where T : class, IEntityWithRelationships
{
if (entitySource != null && entityReference != null && !entityReference.IsLoaded && entityReference.EntityKey != null)
{
if (entitySource.EntityState == System.Data.EntityState.Added) // add the value directly as load will throw
{
if (entityReference.Value == null)
{
entityReference.Value = LoadByKey <T>(entityReference.EntityKey);
}
}
else if (entitySource.EntityState == System.Data.EntityState.Modified || entitySource.EntityState == System.Data.EntityState.Unchanged)
{
entityReference.Load();
}
}
}
static void Listing21_18()
{
Console.WriteLine("{0} : Begin", new StackTrace(0, true).GetFrame(0).GetMethod().Name);
NorthwindEntities context = new NorthwindEntities();
// disable lazy loading
context.ContextOptions.LazyLoadingEnabled = false;
// query for the order
Order ord = (from o in context.Orders
where o.CustomerID == "LAZYK"
select o).First();
// get the entity reference
EntityReference <Customer> customerRef = ord.CustomerReference;
// explicitly load the order
customerRef.Load();
Console.WriteLine("Customer name: {0}", customerRef.Value.CompanyName);
Console.WriteLine("{0} : End", new StackTrace(0, true).GetFrame(0).GetMethod().Name);
}
/// <summary>
/// 保存数据变化到引擎服务
/// </summary>
/// <typeparam name="T">实体类</typeparam>
/// <param name="oldObject">修改前的实体</param>
/// <param name="newObject">修改后的数据</param>
/// <returns>保存结果</returns>
public static string SaveTriggerData <T>(T oldObject, T newObject) where T : class
{
Type etype = oldObject.GetType();
PropertyInfo[] infos = etype.GetProperties();
EntityObject oldEnt = oldObject as EntityObject;
EntityObject newEnt = newObject as EntityObject;
XmlDocument xd = new XmlDocument(); //表示XML文档
XmlDeclaration xde; //表示 XML 声明节点：<?xml version='1.0'...?>
xde = xd.CreateXmlDeclaration("1.0", null, null);
xde.Encoding = "gb2312";
xde.Standalone = "yes";
xd.AppendChild(xde); //<?xml version="1.0" encoding="UTF-8" standalone="yes"?>生成结束
XmlElement xe = xd.CreateElement("table"); //创建一个table根元素
xd.AppendChild(xe); //table根元素创建完成
//查找<table>
XmlNode table = xd.SelectSingleNode("table");
//在<table>之下创建元素<ApplicationSystem>
XmlElement ApplicationSystem = xd.CreateElement("ApplicationSystem");
//人事系统
ApplicationSystem.AppendChild(xd.CreateTextNode("0"));
table.AppendChild(ApplicationSystem);
//在<table>之下创建元素<CompanyCode>
XmlElement CompanyCode = xd.CreateElement("CompanyCode");
PropertyInfo corpProp = infos.SingleOrDefault(p => p.Name == "UPDATEDEPARTMENTID");
if (corpProp != null)
{
object corp = corpProp.GetValue(newObject, null);
CompanyCode.AppendChild(xd.CreateTextNode(corp == null ? "" : corp.ToString()));
table.AppendChild(CompanyCode);
}
//在<table>之下创建元素<OperationUser>
XmlElement OperationUser = xd.CreateElement("OperationUser");
//获取修改人的信息
PropertyInfo userProp = infos.SingleOrDefault(p => p.Name == "UPDATEUSERID");
if (userProp != null)
{
object user = userProp.GetValue(newObject, null);
OperationUser.AppendChild(xd.CreateTextNode(user == null ? "" : user.ToString()));
table.AppendChild(CompanyCode);
}
//在<table>之下创建元素<TableName>
XmlElement TableName = xd.CreateElement("TableName");
TableName.AppendChild(xd.CreateTextNode(oldObject.GetType().Name));
table.AppendChild(TableName);
if (oldEnt == null || newEnt == null)
{
return("");
}
//添加<TableKey>
XmlElement TableKey = xd.CreateElement("TableKey");
table.AppendChild(TableKey);
if (oldEnt != null && oldEnt.EntityKey != null && oldEnt.EntityKey.EntityKeyValues != null && oldEnt.EntityKey.EntityKeyValues.Count() > 0)
{
foreach (var key in oldEnt.EntityKey.EntityKeyValues)
{
//TableKeyName
XmlElement TableKeyName = xd.CreateElement("TableKeyName");
TableKeyName.AppendChild(xd.CreateTextNode(key.Key));
TableKey.AppendChild(TableKeyName);
XmlElement TableKeyValue = xd.CreateElement("TableKeyValue");
TableKeyValue.AppendChild(xd.CreateTextNode((key.Value == null) ? "" : key.Value.ToString()));
TableKey.AppendChild(TableKeyValue);
}
}
//添加<FieldString>
foreach (PropertyInfo prop in infos)
{
if (prop.PropertyType.BaseType == typeof(EntityReference) ||
prop.PropertyType.BaseType == typeof(RelatedEnd) ||
prop.PropertyType == typeof(System.Data.EntityState) ||
prop.PropertyType == typeof(System.Data.EntityKey)
)
{
continue;
}
//关键字段跳过
if (oldEnt != null && oldEnt.EntityKey != null && oldEnt.EntityKey.EntityKeyValues != null && oldEnt.EntityKey.EntityKeyValues.Count() > 0)
{
bool isKeyField = false;
foreach (var key in oldEnt.EntityKey.EntityKeyValues)
{
if (key.Key == prop.Name)
{
isKeyField = true;
break;
}
}
if (isKeyField)
{
continue;
}
}
//生成外键的
if (prop.PropertyType.BaseType == typeof(System.Data.Objects.DataClasses.EntityObject))
{
PropertyInfo refProp = infos.SingleOrDefault(p => p.Name == (prop.Name + "Reference"));
EntityReference reference = refProp.GetValue(oldEnt, null) as EntityReference;
if (!reference.IsLoaded)
{
reference.Load();
}
EntityObject oldEntRef = prop.GetValue(oldEnt, null) as EntityObject;
EntityObject newEntRef = prop.GetValue(newEnt, null) as EntityObject;
foreach (var key in oldEntRef.EntityKey.EntityKeyValues)
{
//在<table>之下创建元素<FieldString>
XmlElement FieldString = xd.CreateElement("FieldString");
table.AppendChild(FieldString);
XmlElement FieldName = xd.CreateElement("FieldName");
FieldName.AppendChild(xd.CreateTextNode(key.Key));
FieldString.AppendChild(FieldName);
XmlElement Field_Old_Value = xd.CreateElement("Field_Old_Value");
Field_Old_Value.AppendChild(xd.CreateTextNode((key.Value == null) ? "" : key.Value.ToString()));
FieldString.AppendChild(Field_Old_Value);
XmlElement Field_New_Value = xd.CreateElement("Field_New_Value");
PropertyInfo[] refinfos = prop.PropertyType.GetProperties();
PropertyInfo refEntProp = refinfos.SingleOrDefault(p => p.Name == key.Key);
object refEntPropValue = refEntProp.GetValue(newEntRef, null);
Field_New_Value.AppendChild(xd.CreateTextNode((refEntPropValue == null) ? "" : refEntPropValue.ToString()));
FieldString.AppendChild(Field_New_Value);
}
}
else
{
//prop.Name
//在<table>之下创建元素<FieldString>
XmlElement FieldString = xd.CreateElement("FieldString");
table.AppendChild(FieldString);
XmlElement FieldName = xd.CreateElement("FieldName");
FieldName.AppendChild(xd.CreateTextNode(prop.Name));
FieldString.AppendChild(FieldName);
XmlElement Field_Old_value = xd.CreateElement("Field_Old_Value");
object oldvalue = prop.GetValue(oldEnt, null);
Field_Old_value.AppendChild(xd.CreateTextNode((oldvalue == null) ? "" : oldvalue.ToString()));
FieldString.AppendChild(Field_Old_value);
XmlElement Field_New_value = xd.CreateElement("Field_New_Value");
object newvalue = prop.GetValue(newEnt, null);
Field_New_value.AppendChild(xd.CreateTextNode((newvalue == null) ? "" : newvalue.ToString()));
FieldString.AppendChild(Field_New_value);
}
}
EngineWS.EngineWcfGlobalFunctionClient engClient = new EngineWS.EngineWcfGlobalFunctionClient();
string rslt = string.Empty;// engClient.SaveTriggerData(xd.OuterXml);
return(rslt);
}